This invention relates to an electrical contact system.
Like the electrical contact system described in my U.S. Pat. No. 4,074,924, this invention finds application in a wide variety of electrical systems, for example systems in which a moving object, driven by electrical power, derives the power from a contact system beneath, about or above the route. Moreover, the contact system of the present invention is also applicable in static systems where it has the advantage that the system is independent of the fixed, prior positions of electrical outlets.
Electrical supply systems are well known in which the source of power is a contact rail alongside a fixed path, for example, as used in electrical railway systems, and particularly in underground electric rail systems or where a power collector collects the electricity from an overhead wire, for example, on certain railway systems on trolley buses and in factories. However, the disadvantage of putting the pick-up rail or track on the ground is clear whenever it may be contacted by a pedestrian. Systems in which overhead rails are used have the disadvantage that contact can be erratic. An example of this erratic contact is the trolley buses where the pick-up frequently breaks contact with the overhead wire, particularly at corners. The result is traffic delays while the contacts are moved back into their correct position on the overhead wires.
In existing static electrical systems, there is the disadvantage that appliances must be positioned near an outlet in the circuit. It is not desirable to move the appliance too far from the outlet since that would involve an excessively long lead. The only alternative is to introduce further outlets.
The present invention is also applicable to illuminated signs, particularly those where it is desired to convey a message in letters or numbers. At present, such signs are either limited to a single message dictated by fixed positions of the lights or, as seen at sports stadiums, highly complex wiring and circuitry, even computer controlled, is used to provide the capability of variable messages.